The invention relates to a vehicle roof having a front cover and a rear cover adjoining each other in the longitudinal direction of the vehicle, and which, in the closed position, cover an aperture in a fixed roof surface; whereby the front cover, as a consequence of a translational movement to the rear, is displaceable into an open position, and the rear cover can be moved into a position permitting retraction of the front cover.
Vehicle roofs of this kind have been known in varying forms of design. One design (German Auslegeschrift 11 62 212 and German Offenlegungsschrift and corresponding U.S. Pat. Nos. 3,075,807 and 4,498,701; and as the rear cover disposed such that it is displaceable upwardly above the fixed roof surface in an essentially parallel manner when the front cover is slid back, with the front cover being accommodated beneath the rear cover. Such an arrangement causes increased air resistance and considerable wind noise at high speeds. Moreover, such roofs do not provide a venting position in which the cover closes the roof aperture but leaves a ventilation gap which lies in an essentially vertical plane.
Another known design of the kind mentioned above (German Patent No. 19 46 161), not only permits displacement of the front cover in a longitudinal direction of the vehicle, but additionally can be upwardly extended at its rearward en into a venting position above the fixed roof surface. In order to create space for a displacement of the front cover to the rear, the rear cover is lowered parallel to the fixed roof surface, and subsequently is slid rearwardly below the fixed roof surface. Such a design has the disadvantage that it considerably reduces the size of the aperture which can be exposed in the longitudinal direction of the vehicle in the open roof position, as the fixed roof surface has to extend rearward of the roof aperture by an amount which at least equals the length of the rear cover. Another disadvantage is that extension of the front cover into the venting position causes the amount of air resistance to be undesirably increased.
German Gebrauchsmuster 81 19 662 discloses a vehicle roof which provides a roof opening in the rear roof area, in which a cover, suitable for closing this roof opening, can be lowered with its front edge below the front edge of the roof opening. However, in this vehicle roof, which has a single cover, the only way to expose the roof opening is through a cumbersome procedure of removing the cover entirely and stowing it away in the interior of the vehicle.